Yes it's doable.
This is what I try to do with some of my mods but progressively, because I'm doing it on my free time.
Especially with the "Remake", so far, I added more than 400 files and I edited all files inside vin_ folders. Also, Ravenger6660 added more than 200 files.
Because doing a mod who overwrite an existed scene, can be overwritten by other mods and can create bugs.
So I created a mega mod who include all modified scenes from modders who wants to join.
So, instead of overwriting a scene, your modifications are added inside other modifications.
Few examples of additions we started:
1 - University courses to finish ...
2- Hunger
3- urge to pee
4- Christianity (Ravenger6660)
5- Police life (Ravenger6660)
6- So I create criminal life and criminal report (9 charges)
......
Examples of goals for future
1- If you don't have specific diplôme/certificats, you cannot have the job
2- If you don't eat, you will die soon
3- If you don't check your urge to pee, thing can happen
4- If you begin to being too prude,
5- Being a policeman and follow his/her adventures
6- More scenes will be added about that.
......